The Statistical Center of the International Bone Marrow Transplant Registry (IBMTR) and the Autologous Blood and Marrow Transplant Registry of North America (ABMTR) coordinates an international effort to collect and analyze data on outcome of blood and bone marrow (hematopoietic stem cell) transplants. The IBMTR, established in 1972, and the ABMTR, established in 1990, involve greater than 400 transplant centers in 47 countries. Participating centers submit data on consecutive transplants to the IBMTR/ABMTR Statistical Center. The Registries have data for greater than 65,000 transplants. These data are used for determining transplant results in specific clinical situations, identifying prognostic factors, comparing transplant regimens, comparing transplant with non-transplant therapy, assessing intercenter variability in diagnosis, practice and outcome, evaluating transplant costs and cost- effectiveness, planning clinical trials or treatment protocols, and developing approaches to evaluating transplant outcome. Statistical Center personnel have a strong record of expert and innovative analyses of these and other issues using IBMTR/ABMTR data. The proposed grant will support continued development of this unique resource of data and statistical expertise. The proposal outlines several enhancements to the Statistical Center's data collection, entry and management system, including addition of cost information, that will ensure availability of demographic, medical and financial data on a large and representative group of transplant recipients for use by the scientific community. The proposal includes several strategies to increase awareness of this resource and enhance its availability to investigators and health policy makers, including development of a public use database. The project will also develop statistical methodologies appropriate for unbiased and efficient analyses of transplant data and provide expert statistical support for studies using IBMTR/ABMTR data.